Yes! And so the lesson is, DO IT! 🙂 Don't regret, just make sure you take those opportunities in the future the next time they present themselves, they don't pop up in life as often as you think. Every situation is different of course, but you gotta grab life by the horns sometimes! For example, one of the best opportunities is with friends when you're boating or swimming. (Them being FRIENDS or at least ACQUAINTANCES is key) A friend is lounging on a float in a pool and those tootsies come magically floating your way, right in front of your face? SCRIBBLE THOSE SOLES with BOTH HANDS. "Sorry, couldn't resist, ha ha" is all you gotta say and move on to do something else. Don't make it weird or awkward afterward and it won't be. Who knows, you may be treated to one of those golden memories like "Who did that? lol. OMG, my feet are SOOOO ticklish" that you will remember forever.
I did that once in one of those lazy river things with a group of friends years ago and was treated immediately afterward to a 5-minute dialogue between three hot chicks about the varying degrees of ticklishness that pedicures produce on their feet. All for a 2-second spontaneous foot tickle and then just remaining silent afterward.
Again, DO IT, and then don't MAKE it awkward or weird afterward, and it won't be 🙂